What this means
Kittens grow fast in the first weeks, so a lag shows early. It is worth watching whether the kitten suckles, whether it moves about like its littermates, whether its weight is going up and whether it is just as curious and playful. A weak newborn that does not suckle, turns cold and goes limp is an emergency, because such kittens can get worse within hours.
Slower growth can have simple causes, such as too little milk or competition from stronger littermates, but sometimes an inborn disease lies behind it. Some metabolic diseases are inherited and begin to show in youth: a kitten may be born weak, or grow normally at first and then begin to tremble, walk stiffly and move less. Brain conditions, such as a build-up of too much fluid, can show as slower growth, an unsteady walk or unusual behaviour.
Write down what you noticed and when: what the kitten weighs, how it suckles, how it moves and whether the lag is becoming clearer. Weakness, trembling or reluctance to jump in a young animal deserves attention rather than waiting for it to pass. When getting a kitten, ask the breeder about the parents' health testing.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your cat.
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An inherited metabolic disease
Some inherited diseases stop the body from properly storing and using its energy reserves. A kitten may be born weak, or begin to tremble and weaken in youth.
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Too much fluid around the brain
A condition, present from birth or developing later, in which fluid builds up and presses on the brain. A kitten may grow more slowly, move unsteadily or behave strangely.
About the condition: Hydrocephalus -
Too little milk or trouble suckling
A weaker or smaller kitten may not get to the milk and fall behind. It can also mean something is wrong with the kitten itself or with its mother.
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Parasites or an infection
Intestinal worms, fleas or an infection sap strength and hold back growth. The kitten may be sluggish, with a belly that looks swollen.
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An inborn problem in an organ or the heart
Sometimes a kitten is born with a fault in how an organ is formed or works. It tires sooner, is weaker and grows with difficulty.
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Inherited nerve and muscle diseases
Some inherited nerve or muscle diseases become clear in youth. The kitten moves unsteadily, with short steps, or trembles.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Whether the kitten suckles and actively looks for its mother
- How it looks compared with the other kittens in the litter
- Whether its weight goes up every week
- Whether it trembles, walks stiffly or avoids jumping
- Whether its head looks unusually large or domed
- Whether it is just as curious and playful as the others
When to book a routine visit
Take the kitten to a vet if it lags behind its littermates, moves unsteadily, trembles or is quieter than usual. A weak newborn kitten that does not suckle needs a vet immediately.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Glycogen storage disease Hormones and metabolism An inherited metabolic disease in which the body cannot properly build and use glycogen, the store of sugar that the muscles, liver and nerves draw their energy from. It shows itself in kittens and young cats.
- Hydrocephalus Nerves and muscles A condition in which too much of the fluid that bathes the brain builds up in or around it and presses on the brain tissue. It can be present from birth and noticed in a kitten, or develop later because of another brain disease or an injury.
- Intestinal worms Parasites Parasites that live in a cat's gut: roundworms, tapeworms and others. They take nutrients, irritate the gut and can slow a kitten's growth.
Body systems: Hormones and metabolism Nerves and muscles Parasites